Folding machine with parti-circular buckle chutes



Oct. 9,. 1956 w, J. HANSON ET AL 2 ,766,040

FOLDING MACHINE WITH PARTI-CIRCULAR BUCKLE CHUTES Filed Dec. 26, 1952 5 Sheets-Sheet l 'INVENTORS' 519/705 [304/ Ja /W7 54 ATTORNEY 9, 1956 w. J. HANSON ETAL 2,766,040

CIRCULAR BUCKLE CHUTES FOLDING MACHINE WITH PARTI- 5' Sheets-Sheet If Filed. Dec. 26, 1952 5 INVENTORJ m3 om m3 3 mm mm H222 m9 mo 5 M. 3N P2 1.- 1 8N m8 $5? m5 Wh m M p I ATTORNEY Get. 9, 1956 w. J. HANSON ETAL 2 766,040

FOLDING MACHINE WITH PARTEGIRCULAR BUCKLE CHUTE Filed Dec. 26, 1952 5 Sheets-Sheet 4 INVENTORS Ale/1 $0300 ZQM /M ATTORNEY Oct. 9, 1956 w, J. HANSON ETAL FOLDING MACHINE WITH PARTI- Filed Dec. 26, l952 CIRCULAR BUCKLE CHUTES' s Sheets-Sheet 5 1N VENTOR-S Wz/f r J:

0/1.:0 7 raw? c/s J o ATTORNEY United States Patent Ofiice Patented Oct. 9 1956 FOLDING MACHINE WITH PARTI-CIRCULAR BUCKLE CHUTES Walter J. Hanson, Port Chester, N. Y., Francis J. Rouan, Darien, Conn., and John William Bach, Port Chester, N. Y., assignors to Pitney-Bowes, Inc., Stamford, Conn., a corporation of Delaware Application December 26, 1952, Serial No. 327,996

9 Claims. (Cl. 270--68) This invention relates to sheet folding and particularly to a sheet folding machine of the buckle chute type which is adapted to-be inexpensively constructed so as to be suitable for small or intermittent users such as offices, clubs, churches and the like, and is an improvement on the folding machine described and claimed in the copending application of Walter 1. Hanson, Serial No. 175,079, filed July 21, 1950.

The folding machine of the present invention, like that uf said application, is characterized by the presence of a plurality of spaced plates arranged on edge, which form the buckle chute, and which contact the sheets to be folded only at their narrow edge portions. It dilfers from the machine of said application, however, in providing a novel cooperating and interlocking relationship between the edges of the plates and the folding rollers as added insurance against the possibility of misfeeding.

According to the present invention, furthermore, .improved plate connecting and spacing means is provided which also serves as an entrance guide throat for the sheet entering one of the buckle chutes.

The present invention also includes a folding machine in which the inner and outer plates are arranged similarly to the showing in said copending application and, in order that the inner plates may serve as a protective housing for the motor which drives the folding machine, a sheet memher is provided which is disposed at its ends adjacent the motor foundation plate and rests against the internal peripheries of the inner plates, to be supported thereby rib-fashion, and thus surround the motor and protect it from lint and dust.

It is an object of the present invention to provide, in connection with certain of the outer plates which form the buckle chutes of a plate-constructed sheet folder, improved means conveniently to support the buckle stops and the controls therefore, and to indicate appropriate settings for the controls to correspond with desired fold lengths.

Another object of the invention is to provide in a sheet folder novel disable means of extremely simple construction for deflecting the sheet away from one of the buckle chutes when a single fold only is desired; said means being especially convenient and uncomplicated to operate between deflecting and non-deflecting positions.

Another object of the invention is to provide in a folding machine having a stacker, a novel sheet feeding hopper unit which can be easily mounted on or removed from the folding machine, together with a flexible, resilient guide strap for the stacker which is retained and tensioned by the feed hopper when in place.

Another object of the invention is to provide a folding machine having a novel readily adjustable sheet feeding hopper having stack controlling features designed to render especial assistance to the operator in the proper feeding of sheets to the folding rollers.

Another object of the invention is to provide a folding machine having a stacker and including novel drive means for the stacker which permits the ready placement and removal of the stacker unit without requiring any special connection or disconnection steps to make the drive operative or to permit stacker removal.

It is another object of the invention to provide a folding machine having an oscillatory drive element for intermittently advancing the stacker drive, together with an extremely simple means for preventing inadvertent oscillatory movement of the stacker drive itself.

It is still another object of the invention to provide a folding machine in which means is provided for controlling the stacker drive to adjust the speed of the stacker to slow speed or high speed in a simple and uncomplicated fashion and thus accommodate the stacker operation to work of different thicknesses.

A further object of the invention is the provision of novel spring means for maintaining the proper pressure of the folding rollers against each other, and extremely simple means for adjusting the spring pressure as required.

A feature of the invention is the provision of disk type resilient cushion feet which are conveniently and simply mounted on horizontal axes and clamped between the end plates and covers of the folding machine.

With the above and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that various changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

A preferred embodiment of the invention is illustrated in the accompanying drawings, wherein:

Fig. 1 is a plan view of a sheet folding machine according to the present invention;

Fig. 2 is a longitudinal section taken substantially on lit 1e 2-2 of Fig. 1;

Fig. 3 is a fragmentary section similar to a portion of Fig. 2, but with the folding plates shown in broken lines, and illustrating the deflector in deflecting position to produce a single fold;

Fig. 4 is a detail section taken substantially on line 4-4 of Fig, 3;

Fig. 5 is an axial section of the folding device of the invention taken substantially on line 5--5 of Fig. 2, the sheet feeding hopper and, for the most part, the operating parts exteriorly of the end plates and within the covers being omitted for purposes of simplicity and clarity;

Fig. 6 is an end elevation of the folding machine of the invention looking in the direction of the arrow 6, Fig. 1, with the hand knob, motor switch operator and adjacent cover plate removed;

Fig. 7 is an end elevation of the folding machine of the invention looking in the direction of the arrow 7, Fig. 1, with the adjacent cover plate removed;

Fig. 8 is a detail section to a larger scale taken substantially on line 8-8 of Fig. 7;

Fig. 9 is a detail section to a larger scale taken substantially on line 9-9 of Fig. 6; and

Fig. 10 is a detail section to a larger scale taken on line 10-10 of Fig. 8.

Referring to the drawings in detail, a frame structure is provided which comprises two side plates 10-10a, preferably of stamped sheet metal, which plates are supported by tie-rods 11a, 11b, 11c, 11d, 11 and 11h.

Folding rollers are provided, as best shown in Fig. 2, and comprise a central roller 12 preferably of rubber or similar composition, also an upper roller 13, lower roller 14 having spaced grooves 14' therein and a side roller 15 having spaced grooves 15 therein, said upper, lower and side rollers being 'frictionally engaged with 3 the central roller 12. The rollers 13, 14 and 15 are preferably metal and have pintle portions 13a, 14a and 15a respectively mounted in the bearings 13b, 14b and 15b..

The central roller 12 has a core or shaft 16 which extends beyond the ends of the rubber roller portion and is supported within bearings 1717.

As best shown in Figs. 8 and 10, each of the side plates 10, a is provided with an opening 18 for the support of the bearing 17 and has three slots 13c, 14c and 150 continuing from the upper, lower and side portion of the opening 18, which slots are adapted to slidably support the bearings 13b, 14b and b respectively. The bearing 17 has a shoulder 19 which fits within the opening 18 and includes a flange 21 which limits the distance that thebearing may move inward. The bearings 13b, 14b and 15b are undercut as indicated at 13d, 14d and 15d, to provide means. .whereby said bearings may be slidably mounted within the slots 13c, 14c and 150 respectively.

The upper roller 13 will normally rest on the central roller 12, the weight of the roller providing a part of the pressure to effect the feed of a sheet when the central roller 12 is rotated. To augment this pressure somewhat and insure proper contact between the rollers at all times, and as best seen in Figs. 6, 7, 8 and 10, spring pressure members are provided in the form of plates 13e each having an integral spring finger 13f. The plates are mounted on side plates 10, 10a by means of screws 13g, one of which passes through an arcuate slot 13h in the plate.. Each of the spring fingers 13f enters one of the slots 13c and presses against the upper surface of one of thebearing members 13b, thus urging the corresponding roller shaft 13a and roller 13 towards the center roller 12. The pressure of spring finger 13 on its bearing can be adjusted by swinging the plate 13e about one of its screws 13g, the other meanwhile sliding in the slot 13h until the desired spring pressure has been attained. This value of spring pressure can then be held by tightening that screw associated with the slot to clamp the plate 13e in the desired position.

The bearings 14b of the roller 14 and 15b of roller 15 are each provided with a similar spring member for holding the roller concerned against the center roll, the parts of the spring members each being similarly designated by literal postscripts, and adjustable in the same manner as the spring members described for roller 13.

A simple arrangement is thus provided for the support of the rollers within the side plates 10 which permits rapid assembly, and provides a substantial and flexible arrangement wherein the rollers 13, 14 and 15, which engage the central roller 12, may yield in accordance with the thickness of sheets which pass therebetween, and such that their spring pressure against the center roller 12 may be easily and individually adjusted to the desired value.

A drive provided for the central roller 12 preferably comprises a pulley 24 which is secured to one end of the central roller shaft 16, which pulley is adapted to be driven by a belt 25 from a motor driven pulley 26. The pulley 26 is mounted on a shaft 27 of a motor 28. A small hand wheel 29 is also secured to the end of the shaft 16 projecting from the opposite side of the machine, as best shown in Figs. 1 and 8. Both the pulley 24 and hand wheel 29, when secured to the shaft 16, act, with any intervening filler pieces employed, to obstruct outward movement of the bearings 17-17, thereby confining the assembly of the central roller and its associated parts within the frame structure in an adequate manner. The outer rollers 13, 14 and 15 are also confined within the side plates 10 of the frame structure inasmuch as the undercut portions 13a, 14d and 15d are arranged to prevent outward movement of the bearings 13b, 14b and 15b.

An arrangement of buckle chutes similar to that shown in the above-mentioned application has been provided, and comprises sheet metal stampings preferably in the form of two elements, namely, an outer buckle chute 4 member 31 and an inner buckle chute member 32, as best shown in Figs. 2 and 5.

The outer buckle chute member 31 comprises a substantially circular contour having one open end or mouth, and an upper extended portion 34 with a cavity 35 therein. Said outer buckle chute member31 also includes an inner opening 36 of substantially circular curvature for the greater portion of its extent.

The inner buckle chute member comprises a substantially circular structure having an outer contour agreeing with the inner contour of the outer buckle chute member, but of slightly smaller diameter. A cavity 39 is provided at one end of said inner buckle chute member, also a central opening 41.

Each of the buckle chute members 31 and 32 also have openings therein, as indicated at 42, 42a and 43, 43a respectively, and are adapted to be assembled on certain of the tie-rods 11 in the manner best shown in Fig. 2. More specifically, the outer buckle chute member 31 is adapted to be supported by the tie-rods indicated at 11a, 11b and 110 and with its lower end resting in suitable groves in the rod 11b, while the inner buckle chute member 32 is adapted to be supported by the tie-rods 11d and Hit. The inner buckle chute member 32 fits within the outer buckle chute member 31 and when assembled within the machine, said members are disposed at right angles to the folding machine rollers.

The assembly of the buckle chute members on the tierods is accomplished by passing the tie-rods 11b, 110 of the outer buckle chute 31 through the enlarged portions of the bayonet openings 42. The tie-rods 11b and 110 are then moved laterally so that their reduced grooved portions 45 are lockingly received in the reduced portions of bayonet slots 42, and the ends of the tie-rods 11b, 11c are then secured to the side plates 10, 10a by means of screws 44. Said grooved portions 45 are spaced along the tie-rods, as best illustrated in Fig. 1, and thus effect the spacing of the buckle chute assemblies therealong. With the members 31 thus assembled, the tie-rod 11a is moved'into the notches 42a whereupon the tie-rod is secured in place by the end screws 13g. Tierod 11f is placed with its grooves receiving the lower outer extremities of the outer buckle chute members 31, and is then fastened in place by additional screws 44 which pass through extension 14: of the slots 14c and are tightened against suitable washer members 44a. Support of the inner buckle'members 32 includes both the tierods 11d, 11h and a tray 46. Said tray 46 is positioned at the lower end of the central openings 41 of the several buckle members and has end prongs secured within the side walls 10 as indicated at 47-47 of Figs. 2 and 3, and further includes angular side extensions 48-48, which are notched as at 49 (Fig. 5) for engagement by the edges of the openings 41 of the inner buckle chute members 32. Tie-rod 11d is fastened to end walls 10, 10a by additional screws 44, while tie-rod 11h passes through the end plates and is secured by suitable spring clips 44'.

Referring to Fig. 2, it will be seen that the cavity 35 of the upper buckle. chute member 31 fits around the upper roller 13, while the cavity 39 of the inner buckle chute member fits around the side roller 15 and into grooves 15 thereof, the cavities being of sufiicient size to clear adjacent portions of the rollers 13 and 15. It will also be seen that a slot 51 remains as a result of the spaced relation between the inner contour of the outer buckle chute member 31 and the outer contour of the inner buckle chute member 32. It will be further noted members by having its flange 54 seated in suitable slots 55 in said buckle chute members. The ends of the plate are bent as indicated by reference characters 57 (Fig. 1) and are attached to end plates 10, a by screws such as screw 59 (Figs. 6 and 7). The free edge of the plate 53 extends downwardly into close proximity to the surface of roller as seen in Fig. 2, and guards against contact therewith by a sheet issuing from between rollers 12 and 13 and destined for mouth 33a.

Settable stop means are provided for determining the fold length of the sheets being folded, and include a curved, slotted support and indicator plate 61 which is fastened to the two central outer buckle chute members 31 by means of screws 63. The plate has a first fold slot 65 with marginal indicia 67 and a second fold" slot 69 with marginal indicia 71, as seen in Fig. l. The first fold stop member assembly includes a first fold stop bar, preferably a metal sheet 73, the body of which is slidably carried in slots 51. Between the buckle chute members the edge of the bar nearest the mouth 33a is bent alternately in opposite directions to form sheet abutment flanges 73a and 73b which insure contact with the sheet at substantially all points along its leading edge and prevent entry of the sheet between the stop bar and either chute member. The bar 73 is connected to an operating arm 75 which carries at its end a clamp screw and nut assembly 77. This clamp assembly is arranged to slide in the slot 65 of plate 61 and to be tightened against the margins of the slot to hold the first fold stop bar 73 in any desired position. It also serves as a finger piece for moving the stop bar to desired adjusted position. A finger 79 projects upwardly from the arm 75 at a point spaced from the clamp assembly 77 and thus maintains the bar 73 in accurate perpendicular relation to the path of sheet travel. Similar reference characters are used to designate the parts of a second fold stop means except that the tens digit used in each case is 8 instead of 7. The stop bar 83 is placed in the other ends of slots 51 to cooperate with sheets entering mouth 33b, andthe operating arm 85 is much longer, and curved to correspond with the curvature of slots 51 so that the clamp assembly and finger piece 87 is extended to an easily accessible position at the back surface of the machine.

It will be noted that the lower ends .of outer buckle chute members 31' are disposed within the grooves 14' of rollers 14 to insure proper guiding of the sheet into the second fold mouth 33b and against the stop bar 83. They are also supported by having their outer edges resting in grooves 90 in tie-bar 11;.

At times it is desired to have a sheet receive a single fold only, and this is accomplished by a simple structure for barring the sheet entirely from the first fold mouth 33a and causing it to be fed to the second fold mouth 33b only. Mounted adjacent the interior surfaces of the end plates 10, 10a and rockable on the tie-rod 11a as a pivot are a pair of curved arms 91 preferably formed integrally with and bent at right anglesto the ends of a bent slotted plate 93 extending the width of themachine. The slots in the plate, indicated by reference characters 95 are spaced to register with and receive the spaced outer buckle chute members 31 therein. The upper flange 97 of the plate serves as a convenient manual control element and also carries measurement indicia 99 (Fig. l) to aid in centering sheets on the machine as will hereinafter appear. The lower margin 101 of the slotted portion of the plate is bent at a suitable angle todeflect sheets issuing from the bite of rollers 12, 13 away from mouth 33a and into the bite of rollers 12, 15.

By means of the flange 97 the mouth barrier structure can be manually moved to either of two positions, the inoperative position of Fig. 2 in which two folds are performed on each sheet, or the operative position of Fig. 3 in which one fold only is permitted. Means are provided'for holding the barrier structure in either of these two positions and include retaining holes or recesses 103' and 103a in the arms 91 cooperating with suitable spring pressed poppet devices 105 on the end plates 10, 10a. One of the poppet devices is illustrated in detail in Fig. 4 and includes a flange 107, an integrally attached hollow internally and externally threaded stem 109 passing loosely through a suitable opening 111 in the end plate 10 and clamped therein by a flat nut 113. Within the hollow stern 109 is a ballpoppet 115 which projects beyond the face of the flange 107 through a central opening in line with the hollow stem, but which is too large in diameter to pass through the opening. The ball 115 is maintained in projected position by a spring 117 held in the bore of the stern 109 by a retaining screw 119. The latter may be jammed by a lock nut, 121 which simultaneously prevents inadvertent loosening of nut 113. Due to the size of the opening 111, the poppet device may be accurately positioned to place the margin 101 of plate 91 as close as possible to the roller 15 when the plate is in lowered position to prevent any possibility of a sheet entering the first fold mouth 33a. The balls 115 then engage either in openings 103 to hold the barrier device in lowered position, or in openings 103a to hold the same in raised position with suflicient frictional resistance for firm retention, but so that manual shifting from one position to the other is readily accomplished. If the degree of frictional resistance requires adjustment, this can be elfected through the otfices of screw 119. The arms 91 also preferably include stops 121 which are arranged to strike tie bar 11 and prevent excessive swinging of the arms past the raised position as determined by the poppets 105 and openings 103a.

The tray 46, which holds the lower portions of the inner buckle chute members 32 in horizontally spaced relation, also provides a base for the support of a pair of motor brackets 123, within the openings 41 of said inner buckle chute members. The brackets 123 are at one side of the machine and underlie the bosses 124 at the ends of the housing of motor 28 which is held in place by straps 125 which can be tightened by screws 127. Surrounding the motor and in firm contact with the edges of the inner buckle chute members 32, at their openings 41 is a flexible shield 129 which extends from one edge of the tray 46 to the other and from end plate 10 to end plate 10a. The shield 129, with other parts of the device, forms a motor enclosing housing which prevents dust and lint from affecting motor operation and materially enhances the appearance of the folding machine. Within the housing formed by shield 129 and mounted on the end plate 10a is a bracket 131 which carries a push button on-off" switch 133, which projects through a suitable opening 135 in the plate 10a, and a relay 137, as shown in Fig. 6. Conductors 139, 139a, 139b, 1390 and 139d interconnect the switch 133, relay 137 and motor 28 to make up the motor circuit which is con nected at its ends to the conductors 141, 141a making up the cord 143 which leads to the exterior of the machine for connection with a suitable source of electric power. A molded manual push button 145 which fits over the end of the operator of switch 133 projects beyond the end plate 10a and is provided with an integral shoulder 147 for a purpose which will hereinafter appear.

sheet supporting feed hopper or plate is provided as indicated at 149, and comprises a flat piece of sheet metal having two side walls 151 bent upwardly therefrom with notches 153 in their upper edges. Also formed at the same time as the bending of walls 151 are the lanced ears 155 which have downwardly directed notches 157, best seen in Fig. 3. The feed plate is stamped with openings 159, pairs of which form means for positioning an edge guide 161 which has lanced ears 163 for receptron in the openings 159. The guide 161 includes the sheet e contacting flange 165 and a directing fin er 167 bent therefrom to overlie the sheet margin a nd assist in the manual feeding of the uppermost sheet of a shingled stack into the bite of rollers 12, 13. An th edge guide 169 is preferably arranged for continuous lateral adjustment and includes a manual control and clamping means 171 designed to cooperate with an appropriate downwardly turned flange 173 formed at the free edge of plate 149. The guide 169 also includesan upstanding edge contacting flange 175 and a directmg finger 177 similar to flange 165 and finger 167. Approximate centered position of a sheet of any size can be brought about by adjusting the guides 161 and 169 with reference to the indicia 99 on manual control flange 97 of the barrier mechanism. An extension plate 179 is provided centrally of the feed plate 149, carries lanced finger 181 for cooperation with openings 183 in the feed plate, and serves to assist in feeding when longer than normal sheets are being folded, or a large stack is being shingled and fed at one time.

The feed plate is assembled on the folding machine by inserting one margin thereof between the tie-rod 11a and the tie-rod 11e therebeneath, and seating the notches 157 on the tie-rod 11e when the notches 153 become engaged by the tie-rod 11a. The feed plate is thus adequately supported and has a portion thereof extending toward the bite between the rollers 12 and 13 with the plate sloping slightly downwardly towards the rollers. During a folding operation, sheets are stacked within the feed plate with the leading ends thereof feathered toward the folding rollers 12 and 13, the uppermost sheet being closest to the rollers. Feeding is then best effected by placing a rubber cot on the index finger of the operator and wiping the same across the top of the stack in a rhythmical fashion. Surprising speed approaching that of some power fed folding machines can be accomplished by operators with a little experience.

In order to accommodate the folded sheets as they issue from the bite of the rollers 12, 14, a stacker mechanism is provided which includes a plate 185 having downwardly turned side flanges 187. An ear 189 projects from one end of each of the flanges and is provided with an end notch 191 and a bottom notch 193. Notch 191 is arranged to receive the crossbar 11f when the notch 193 rests upon crossbar 11g, and between these elements the stacker is firmly supported with the plate 185 extending in a slightly downwardly sloping direction away from the rollers 12, 14. In the ends of the flanges 187 are oppositely facing pairs of notches 195 and 197, the former sl-idably carrying bearings 199 and the latter bearings 201. Bearings 199 support a rotatable shaft 203 on which are fixedly mounted a pair of belt drive pulleys 205, and drive disk 207 carrying a radial drive arm 209. Bearings 201 support a shaft 211 which carries a pair of idler pulleys 213. Stacking belts 215 are disposed about the pulleys and the parts are so proportioned that the upper reach of each belt lies in substantial contact with the upper surface of plate 185. Springs 217 positioned in the notches 197 and supported on suitable projecting ears 219 urge the bearings 201 away from bearings 199 and thus keep the belts 215 tight. An upwardly curved terminal work receiving surface formed by a plate 221 may be fastened to the discharge end of plate 185 if desired as seen in Figs. 1 and 2.

In order to drive the belts slowly so as to move the folded sheets gradually away from the discharge point, means are provided for taking motion from shaft 16 and translating it into slow belt motion as shown in Figs. 6, 8 and 9. As can be seen in Figs. 6, 8 and 9, an eccentric member 223 with a radial web 225 is mounted on shaft 1.6 and keyed thereto and to the handle member 29. Another shaft 227 is rotatably mounted in a bearing 229 mounted in end plate a in line with the normal position of pulley shaft 203 when the stacker unit is in place. Rockable on shaft 227 is an eccentric follower member 231 which has a pair of substantially parallel arms 233 and 235, which lie in contact with the periphery of eccentric 223, one on each side of the web 225. While not required, a spring 237 preferably biases the follower 231 in one direction against the eccentric for quieter operation. A one-way drive mechanism is provided between the follower 231 and the shaft 227, and is shown as including a pawl 239 rock-ably mounted on the follower and urged by a spring 241 into contact with the periphery of a ratchet wheel 243 rigidly connected to the shaft 227. The parts are so designed and positioned that each rotation of the eccentric 223 causes the pawl to first ratchet over two teeth of the wheel 243 and then feed the wheel a distance of two teeth in an anticlockwise direction as seen in Fig. 6, thus imparting to shaft 227 a very slow intermittent rotation which is about $5 of the speed of the shaft 16. The speed of shaft 227 can be varied to a certain extent, however, by means of a speed control lever 245 which is rockable on the shaft 227 and extends beyond the periphery of the end plate 10a. In the form shown the lever is setta-ble to either of two positions in which it is retained by detent means consisting of an embossed projection 247 on the lever which lodges in either of two openings 249 and 251 in the end plate 10a, the lever being movable from one to the other due to its inherent resilience. A pawl lifter 253 is integral with the lever 245 and serves, when the lever is positioned in its lower position with projection 247 in opening 251, to underlie the pawl 239 and keep it from contact with the teeth of ratchet wheel 243 for one-half of the normal stroke so that the wheel 243 will be rotated only one tooth per turn of shaft 16 or at about $4 of the speed of shaft 16. When the lever 245 is in upper position with its projection 247 engaged in the opening 249 as shown in Fig. 6, the pawl lifter 253 is out of range of the pawl 239 and is inoperative.

The shaft 227 carries at its inner end rigidly connected thereto a crank arm 255 having an axial projection 257 arranged to swing in a cylindrical locus which intersects the drive arm 209 whenever the stacker is in place on the machine, thus driving the shaft 203 and the stacker belts at the speed of shaft 227. Also rigidly connected to the inner end of shaft 227 is a drum member 259 of substantially the same diameter as the adjacent periphery of bearing 229. About the two adjacent peripheries of bearing 229 and drum 259 is a helical spring 261 which grips the surfaces lightly and which is wound in a direction such that the drum and shaft will be permitted to rotate anticlockwise (as seen in Fig. 6) but such that their clockwise rotation will be strongly resisted, i. e. the spring is wound in a clockwise direction starting from the right end in Fig. 9 and proceeding towards the left. Thus the oscillating movement of follower 231 will move the shaft in the desired direction only and the tendency of friction to bring about retrograde motion of shaft 227 is effectively overcome. By means of the foregoing mechanism the stacker belts 215 are driven slowly in a direction to carry folded sheets gradually away from the discharge of rolls 12, 14 thus maintaining them in an orderly shingled condition whereby a large number of sheets may be folded consecutively before an interruption of operation for clearing away the completed work becomes necessary. This materially enhances the productive potential of the machine which is capable of remarkable folding speeds with a little experience on the part of the operator.

In order to insure proper separation of the folded,

sheets from roller 12 and accurate placement of the sheets on the stacker belts, a rectangular crossbar 263 extends between the end plates 10, 10a in close proximity to the surface of roller 12 and carries a plurality of downwardly sloping guide fingers 265 which serve to redirect any sheets which might tend to leave the rollers in an upward direction.

The folded sheets are held in proper ordered condition on the stacker belts by a pair of straps 267, one for each of the belts 215, and each comprises a generally L-shaped spring steel member, the longer arm 269 of face of the plate or the work thereon. The shorter l l l i 9 arm 271 of the strap 267 has a tensioning function which will hereinafter appear. Between the arms is a loop portion 273 designed to hook over tie-rod 11c and repose in suitable positioning grooves 275 formed in the surface thereof. In mounting the straps 267, they are placed on the tie-rod 11e prior to the placing of the feed plate 149. In this condition the short arms 271 are disposed with their ends slightly higher than shown in Fig. 2. When the feed plate 149 is set in place, its bottom surface overlies the loop portions 273 of straps 267 and retains them securely in place in grooves 275. At the same time the under surface of the feed plate 149 strikes the free ends of short arms 271 and depresses them slightly so as to flex the straps 267 a small amount, mainly in the long arms 269 thereof near the loop portion, and thus exert a slight retaining pressure against the upper surfaces of stacker belts 215.

In order to protect parts of the mechanism from dust and damage and to improve the appearance of the machine, the ends of the outer surfaces of the end plates 10 and 10a are enclosed 'by cover members 277 and 277a respectively, which are attached to the end plates 10, 10a by suitable screws 279 passing through openings in the end plates from the inside surface thereof. 277a is provided with a suitable opening 281 for the passage of hand wheel 29 and an opening 283 which is large enough to pass the manually engageable end of the switch operator 145 but smaller than the flange 147 so that the operator is retained in place on the switch when the cover plate 277a is in place. A slot 289 at the edge of the cover member provides for extension of the lever 245 exteriorly of the cover to a manually engageable position. The cover member 277 is slotted at its edge to pass the power supply cord 143, as indicated by reference character 291, Fig. 6.

In keeping with the simplicity and inexpensive structure of the entire folding machine, front supporting feet 293 are provided in the form of rubber rings which are easily assembled on the front lower tie-rods 11g. Similar ring-shaped feet 295 are provided for the rear of the machine and are fastened :between each cover member 277 or 277a and its corresponding end plate 10 or 10a in cover notches 297 provided therefor. They are fastened by screws 299 which assist the screws 279 in mounting the cover members on the end plates.

Having described the invention, what is claimed is:

1. In a sheet folding machine, the combination with sheet folding rollers including a central roller having an upper roller, lower roller and side roller frictionally engaged therewith; of buckle chutes comprising a group of vertically disposed and horizontally spaced flat plate structures having horizontally aligned central openings and aligned slotted portions therein; stop means, the slotted portions cooperating with the rollers and stop means to effect buckling and folding of sheets fed thereto; supporting means for said vertically disposed plate structures; a power drive for said central roller including a motor mounted within the central opening in said plates; and a housing member comprising a shield of sheet material overlying said motor and engaging against the inner peripheral edges-f said plate structures adjacent their central openings for rib-fashion support of said shield.

2. In a sheet folding machine, the combination with sheet folding rollers including a central roller having an upper roller, lower roller, and side roller frictionally engaged therewith; of buckle chutes comprising a group of vertically disposed and horizontally spaced fiat plate structures having horizontally aligned central openings and aligned slotted portions therein; stop means, the slotted portions cooperating with the rollers and stop means to effect buckling and folding of sheets fed thereto; supporting and spacing means for said vertically disposed plate structures including a sheet metal tray extending through said central openings near the bottoms thereof and having Cover plate a pair of notched edges'interlo'cking with said plate structures; a power for said central roller including a motor mounted within the central opening in said plates and resting on said tray; and a housing member comprising a shield of sheet material overlying said motor and engaging against the inner peripheral edges of said plate structures adjacent their central openings for rib-fashion support'of said shield, the latter extending from one notched edge of the tray to the other.

3. In a sheet folding machine, the combination with sheet folding rollers; of sheet buckle chutes and stop elements cooperating with the folding rollers to effect sheet buckling and sheet folding operations, wherein the sheet buckle chutes comprise a plurality of horizontally spaced flat plate structures vertically supported at right angles to the folding rollers, each plate structure comprising an inner and outer plate, said outer plate being parti-circular and having an opening therein, each inner plate fitting within an opening in the outer plate and having the periphery thereof spaced relative to the inner periphery of the opening of the outer plate, and each outer plate and its respective inner plate forming an open mouth at the end adjacent the rollers, whereby entry to the space between the peripheral edges is provided for the sheet during a sheet feeding operation, and wherein the stop elements comprise two sheet metal bars extending perpendicular to said plate structures and through the spaces between the peripheral edges of the outer and inner plates and adapted for edgewise movement through said spaces to alter the length of the folds produced in the folded sheets, each of said bars being notched at the edge directed towards said mouth and having the marginal portions between notches bent substantially perpendicular to the plane of the bar alternately in opposite directions.

4. In a sheet folding machine, the combination with sheet folding rollers having a central roller and upper, lower and side rollers in frictional sheet-feeding engagement with the central roller, said side roller having annular grooves; of upper and lower buckle chutes having entrance openings respectively above and below said side roller; and stop elements in said buckle chutes cooperating with said rollers to effect sheet buckling and folding operations, the buckle chutes comprising a plurality of fiat plate structures spaced transversely of the machine and vertically supported at right angles to the axes of the folding rollers, each plate structure comprising inner and outer plates, each of the outer plates having a parti-circular inner edge partially enclosing a parti-circular outer edge of an associated inner plate and having the inner edge of the outer plate slightly spaced from the outer edge of the inner plate and forming therewith the walls of the chute, portions of each outer plate terminating adjacent said folding rollers to provide passage space leading to and from said chutes and feed rollers, the inner plates having portions extending into annular grooves in the side roller and into close proximity to the central roller to guide a sheet past the side roller into the buckle chutes.

5. A sheet folding machine as defined in claim 4, in which the outer plates have terminal portions adjacent the lower roller extending into overlapping relation with the periphery of the lower roller to guide a sheet past the lower roller into the lower chute.

6. A sheet folding machine as defined in claim 4, in

which the space between the outer peripheral edges of the transversely spaced inner plates at the passage space leading to and from the upper chute and the central roller is bridged by a transversely extending guide plate to direct the leading edge of a sheet into the upper chute.

7. A sheet folding machine as defined in claim 6, in

.which said guide plate has one edge overlying the side roller and the other edge in the form of an annular flange extending into aligned notches in the peripheral edges of the inner plates.

8. A sheet folding machine as defined in claim 4, in which the stop elements in each buckle chute comprises '11 a bar extending transversely of the plate structure through the space between the adjacent edges of the inner and outer plates, said bar being movable along its chute to vary the efiective length thereof and being guided in such movement by engagement with the adjacent edges of the 6 inner and outer plates.

9. A sheet folding machine as defined in claim 8, in which an index plate following the contour of the buckle chutes is carried by said pair of outer plates and constitutes part of the means for fixing the stop means in 10 adjusted position.

References Cited in the file of this patent UNITED STATES PATENTS 1,606,459 Waterworth Nov. 9, 1926 15 12 Tufts Aug. 28, Spiess Aug. 20, Hitchcock Sept. 29, Schutt June 5, Holmes Feb. 8, Rouan et a1 Mar. 18,

FOREIGN PATENTS Germany Aug. 28, 

